Six Degrees of
Separation

In July 2006, Eric Horvitz and Jure Leskovec as part of a research project
at Microsoft Research captured a snapshot of anonymized
patterns of communications across the globe within the MSN Messenger
system.The dataset contained 30
billion conversations among 240 million people, representing what was estimated
to be approximately half of all instant messaging communications in the world
during that period of time.No text
was captured—only statistics were gathered. From the dataset, they
constructed a “communication graph” with 180 million nodes and 1.3
billion undirected edges, creating the largest social network constructed and
analyzed at the time. As part of their studies they investigated on a
planetary-scale the oft-cited report that people are separated by “six
degrees of separation” and found that the average path length among
Messenger users communicating with one another during the month of July 2006 is
6.6. They also found that people tend to communicate more with each other when
they have similar age, language, and location, and that cross-gender
conversations are both more frequent and of longer duration than conversations
with the same gender.